The Implications of Land Use, Cover, and Management Change in the Chesapeake Bay Watershed

The Science Issue and Relevance
The population of the Chesapeake Bay Watershed (CBW) has more than doubled since 1950 and is expected to continue growing at over 1-million persons per decade. Population growth due to migration and natural increase has led to the conversion of forests and farms to urban development. Agriculture has intensified leading to localized increases in manure. These and other activities have increased nitrogen, phosphorus, and sediment inputs to the Bay. To restore the health of the Bay, nutrients and sediment must be reduced through a variety of actions- many of which involve changes in land use, cover, and management. Understanding how land use/cover have changed through time; what drives the change; how land use/cover change in the future; and what consequences to stream flow, water quality, and wildlife habitat from plausible future land change scenarios result; are questions that need to be addressed to help manage and restore the health of the CBW.

Figures 1a & 1b. Example 2010 (1a) and future 2040 (1b) trend development in Frederick County, MD as modeled using the Chesapeake Bay Land Change Model.

Methodology for Addressing the Issue
The Eastern Geographic Science Center (EGSC) is leading efforts to characterize, monitor, and model land use and land cover change in the CBW by producing data used to help quantify the production and delivery of pollutants to the Bay, target the implementation of Best Management Practices (BMPs), and assess the vulnerability of farms and forests to conversion to development. Assessing changes in land use/cover plausible urban development scenarios from 2015 to 2070; analyzing the effects of spatial and temporal impervious surface patterns on stream flow; assessing the combined effects of urban development and sea-level rise on black duck habitat; and disseminating the data and analyses through web-based tools and visualizations are current activities.

Future Steps Develop annual land cover change datasets from the Landsat archive; oversee the interpretation of 1-meter aerial and LiDAR elevation to target BMPs for water quality; and refine the land change model to better represent urban infill and redevelopment activities.